Image: NASA/Bill Ingalls
Light pollution can make it hard for many of us to see the stars.
Richard Bunting explores the issues, and suggests some fantastic Dark Sky locations to experience around the world.
There can be few greater pleasures than gazing up at a starry sky. I have fond childhood memories of heading out to the garden on clear nights with a flask of hot chocolate – and with my father on hand to point out Jupiter, the Plough, and Cassiopeia.
These days, though, fewer of us are able to have a really good stargazing experience. Light pollution is making it harder and harder to appreciate the beauty of the night sky, and people in some inner-city areas may find it difficult to see more than a handful of stars on a clear night.
In many areas, of course, artificial light is essential to illuminate streets or hazardous areas. Lighting also allows sports and other activities to take place after dark.
But artificial light such as street and security lighting, that shines where it’s not really needed, can cause problems – and not just with our ability to see the stars. People living in areas of high light pollution have complained of sleep disruption and other health issues. And light pollution can also affect the behavioural patterns of wildlife. There is an environmental impact, too: unnecessary lighting wastes energy and money.
Above: the Iberian Peninsula and US Gulf Coast lit up at night. Images: NASA
Taking a look at the constellation of Orion is one way to assess the level of light pollution wherever you are in the world. It’s one of the most distinctive constellations, so is not hard to identify: three bright stars form The Hunter’s belt, and an arch of stars represents his bow.
In the southern hemisphere, of course, The Hunter – also known in Australia as The Saucepan – is upside down. But that distinctive arrangement of stars is still extremely easy to spot.
On Orion’s shoulder is the orangey-red star of Betelgeuse, one of the most famous stars in the night sky. Betelgeuse is a star that’s near the end of its lifetime, and is due to perform a spectacular supernova explosion some day.
When this happens, Betelgeuse could be as bright as the moon, and visible during the day – but don’t hold your breath, as this exciting event could still be thousands of years away. Or it could happen tomorrow. Nobody really knows.
If the light pollution in your area is minimal, you may also be lucky enough to make out Orion’s sword: three bright stars in a vertical line south of Orion’s belt. The middle of these is actually a nebula – an area where new stars are being formed. If you look at this with binoculars or a telescope you may be able to make out the cluster of stars.
To assess your light pollution levels, having identified Orion, count the stars you can see within the rectangle formed by the four bright stars of Betelgeuse, Bellatrix, Rigel and Saiph (Orion’s shoulders and knees).
If you can count fewer that 10 stars, then the light pollution levels in your location are pretty bad. With little or no light pollution, you should be able to make out 30 stars or even more.
Fortunately there are still plenty of places – across the UK, Europe and worldwide – where light pollution levels are low and you can enjoy the night sky as it’s meant to be seen. Other locations offer access to specialist equipment and information to help you discover the stars and learn more about them. Here’s our pick of some of the best worldwide stargazing destinations.
The UK has some of the largest areas of dark skies in Europe. Galloway Forest Park is the UK’s first Dark Sky Park and is one of the darkest places in Scotland. Over 7,000 stars and planets are visible with the naked eye, with a clear and bright Milky Way arching across the sky.
There are three Visitor Centres in the forest, and all will give you a fabulous view of clear, starry skies – but Clatteringshaws, in the unlit heart of the Forest Park, has the best views of all.
In the Peak District, head for Surprise View, near Hathersage – a Dark Sky Discovery Site, which is one of the best stargazing spots in England. Here it’s possible to see the Milky Way with the naked eye, amongst other night sky wonders such as the Andromeda Galaxy, 2.5 million light years away.
If you’re interested in finding out more about the night sky, Jodrell Bank Discovery Centre, near Macclesfield, is a great place to start. In the Space Pavilion, you can find out everything you need to know about black holes and the Big Bang. The famous Lovell telescope can be visited, and there are talks, lectures and hands-on night sky events each month.
There is also a wealth of information on Jodrell Bank’s website at www.jb.man.ac.uk/astronomy/nightsky, including tips on spotting the constellations, and a monthly update on what to look out for on a clear night.
For more Dark Sky Discovery Sites in the UK see www.darkskydiscovery.org.uk.
The Pic du Midi International Dark Sky Reserve, France (known in France as Réserve Internationale de Ciel Étoilé du Pic du Midi) is in the beautiful Haute-Pyrénées region in south-west France. There’s an observatory here, at 2,877m high up in the mountains of the Pyrénées – take the cable car from the resort town of La Mongie for a spectacular view of the sunset and an evening of stargazing. There are exceptionally dark night skies over the Pyrénées Mountains and you’ll see galaxies, star clusters and planets, using telescopes and the naked eye. You can even spend the night (selected dates for evening and overnight visits – see www.picdumidi.com for details).
One reason why the light pollution here is so low is because of the efforts of the local communities – 251 in total – to manage outdoor lighting levels using new lighting technologies. Light pollution has been reduced by 85 percent in recent years, while maintaining safe lighting levels for residents and visitors.
The Kerry International Dark Sky Reserve, Ireland, is one of only three gold tier dark sky reserves on the planet – making it one of the best places in the northern hemisphere to see stars. On clear nights the sky in this part of southwest Ireland is stunning. The Milky Way, Andromeda Galaxy and star clusters can all be seen with the naked eye. The reserve is on the Ring of Kerry Tourist route, so is also one of Europe’s most accessible dark sky reserves – with facilities such as accommodation and places to eat within the reserve itself.
The world’s largest dark sky reserve is Aoraki Mackenzie in New Zealand. The Mackenzie Basin in the South Island has skies that are almost entirely free from light pollution, with the clearest, darkest and most spectacular night sky in New Zealand. The villages of Tekapo, Twizel and Mt Cook are within the reserve, and there are a number of companies operating night sky tours – making it easy for visitors to experience some truly magnificent stargazing. Highlights include the Magellanic Clouds – satellite galaxies to the Milky Way that are only visible in the southern hemisphere.
Some of the darkest skies in the USA can be found at Natural Bridges National Monument in Utah. Here, in the world’s first International Dark Sky Park, it’s possible to see as many as 15,000 stars and enjoy the stunning river of light formed by the Milky Way as it rises over Owachomo Bridge. There are evening astronomy sessions, with telescopes available, held at the Visitor Centre – learn about astronomy, light pollution and night sky protection, and get a closer look at celestial bodies, including planets and stars.
Wood Buffalo National Park is the largest National Park in Canada, straddling the Alberta and Northwest Territories boundary. It has been given Canadian Dark Sky Preserve designation by the Royal Astronomical Society of Canada, and as well as having stunning starry skies, is home to North America’s largest native land mammal, the wood bison.
For more dark sky locations worldwide visit http://www.darksky.org
All great dark sky locations should be protected from light pollution, to ensure excellent stargazing opportunities for future generations. For those wanting to help, there are campaigns that are fighting for darker skies and citizen science programmes that can help researchers to assess the quality of the night sky.
In the UK the Campaign to Protect Rural England has an ongoing dark skies campaign: www.cpre.org.uk/what-we-do/countryside/dark-skies
The Globe at Night is an international citizen-science campaign to raise awareness of the impact of light pollution, and offers information on how to measure night brightness in your location by observing constellations: www.globeatnight.org
Green Adventures May 2015